“You can never be sure how many beers you had last night” has been called the “Heineken Uncertainty Principle”—a physics pun on Heisenberg’s uncertainty principle. The Heineken Uncertainty Principle was posted in the newsgroup comp.sources.games on June 3, 1987.
   
   
Wikipedia: Heineken
Heineken Lager Beer (Dutch: Heineken Pilsener), or simply

(Dutch pronunciation: [ˈɦɛinəkən]) is a pale lager beer with 5% alcohol by volume produced by the Dutch brewing company Heineken International. Heineken is well known for its signature green bottle and red star.
 
Wikipedia: Uncertainty principle
In quantum mechanics, the uncertainty principle, also known as Heisenberg’s uncertainty principle or Heisenberg’s indeterminacy principle, is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position x and momentum p, can be known.
 
Introduced first in 1927, by the German physicist Werner Heisenberg, it states that the more precisely the position of some particle is determined, the less precisely its momentum can be known, and vice versa.
       
Chicago (IL) Tribune
An Accused Man`s Masterful Battle Of Legal Maneuvers
March 20, 1987 | By Eric Zorn.
Richard David Lowe says he was arrested by the police while sitting under the influence, SUI, in a parked car.
 
It was Founders` Day in Algonquin, and, he admits, he had consumed his share of the customary beer and bratwurst refreshments at that magnificent annual event in the Gateway to the Chain O` Lakes. How many beers he is not sure—chalk it up to the Heineken Uncertainty Principle—but he remembers that he did not feel particularly drunk.
 
Google Groups: comp.sources.games
v01i040: fortune - quote for the day, Part14/16
.(JavaScript must be enabled to view this email address)
6/3/87
(...)   
The Heineken Uncertainty Principle:
You can never be sure how many beers you had last night.
 
Google Groups: comp.windows.x
one *small* change to xphoon.c
Jef Poskanzer
9/3/88
(...)
The Heineken Uncertainty Principle: You can never be sure how many beers you had last night.
 
Google Groups: soc.culture.jewish
Racist jokes  
Dan Howell
12/9/88
(...)
The Heineken Uncertainty Principle:
You can never be sure how many beers you had last night.
 
Google Groups: alt.rock-n-roll
Pearl Jam/Red Hot Chilli Peppers
Victor Estrada
12/17/92
(...)
The Heineken Uncertainty Principle:
You can never be sure how many beers you had last night.
     
Google Groups: comp.lang.ada
ANDF - some information
Bob Wells #402
12/10/93
(...)
“The Heineken Uncertainty Principle:
You can never be sure how many beers you had last night.”
 
Google Books
Denial Is Not a River in Egypt
By Sandi Bachom
Center City, MN: Hazelden
1998
Pg. 25:
The trouble with being a drunk is that you can never be sure how many beers you had last night.
 
Twitter
fortune_cookie_‏
@fortune_cookie_
The Heineken Uncertainty Principle:
You can never be sure how many beers you had last night.
9:07 AM - 2 Mar 2009
 
Facebook
Rathi Rocks.
September 12, 2011 ·
You can never be sure how many beers you had last night.
   
Google Books
A Neutron Walks Into a Bar…
Random Facts about Our Universe and Everything in It
By Science140
Dublin: Hachette Books Ireland
2012
Pg. ?:
The Heineken Uncertainty Principle says: ‘You can never be sure how many beers you had last night.’
 
FacebookCharroz
July 7, 2013 · Thimphu, Bhutan ·
You can never be sure how many beers you had last night.
=The Heineken Uncertainty Principle